The inventive concept disclosed herein relates to a method and apparatus for determining the size distribution of particles.
Various methods for measuring the size distribution of small particles exist. These methods include using sieves, sedimentometry, laser diffraction, dynamic light scattering, and use of a microscope. Using sieves involves separating particles and measuring their size distribution based on varying mesh sizes of sieves. Sedimentometry, which is measurement using a sediment meter, measures the rate particles fall through a viscous medium, which rate is then correlated to particle size. Laser diffraction and dynamic light scattering use laser light directed at the particles. For laser diffraction, particle size distribution is determined based on the diffraction pattern of light scattered by the particles; for dynamic light scattering, particle size distribution is determined based on the changes in intensity of light scattered by particles in a solution. Microscopes can be used to directly measure particle sizes.
A problem with the above methods is that they are laborious and time-consuming, require specialized and expensive equipment such as lasers or an appropriate microscope, or both. Each method also typically requires trained personnel to use the equipment accurately. Such requirements limit these methods to industrial and laboratory applications. A method for measuring the size distribution of small particles that could be more readily used in a casual environment (e.g., in an average home) by individuals would be desirable.